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Identification of a potent neurotrophic substance for ciliary ganglionic neurons in fetal calf serum as insulin‐like growth factor II
Author(s) -
Motoike Toshiyuki,
Unsicker Klaus
Publication year - 1999
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19990515)56:4<386::aid-jnr6>3.0.co;2-d
Subject(s) - affinity chromatography , ciliary neurotrophic factor , in vivo , size exclusion chromatography , biological activity , neurotrophic factors , neurotrophin , growth factor , bioassay , chemistry , biology , in vitro , biochemistry , receptor , genetics , microbiology and biotechnology , enzyme
When fetal calf serum (FCS) alone is used as a trophic support for cultured chicken parasympathetic ciliary ganglionic (cCG) neurons, it does not show any survival‐promoting effects on these neurons. When FCS is applied to heparin‐affinity chromatography, however, potent survival‐promoting activity is obtained in the fraction eluted with 0.5 M NaCl. Using cCG neurons as a bioassay system, this neurotrophic activity was purified by a combination of heparin‐affinity chromatography, gel filtration chromatography, and Sep‐Pak C18 cartridge. The 40–50‐kDa fractions from the gel filtration column with strong survival‐promoting activity were shown to contain insulin‐like growth factor II (IGF‐II) by immunoblot analysis. By acidification, the survival‐promoting activity and IGF‐II were translocated together from the 40–50‐kDa to the 7–10‐kDa fractions, and the survival‐promoting activity in the 7–10‐kDa fractions was blocked by an anti‐IGF‐II neutralizing monoclonal antibody. These results indicate that the neurotrophic substance in 0.5 M NaCl‐eluate from heparin‐affinity chromatography is IGF‐II and that mechanisms may exist in vivo for the activation of latent IGF‐II, whose biological effects may be blocked by its specific binding proteins. J. Neurosci. Res. 56:386–396, 1999. © 1999 Wiley‐Liss, Inc.